Weekly Recap
Early this week, George headed over to Massachusetts Maritime Academy
to meet with the team of cadets that has been deploying eMOLT sensors as
part of their research project monitoring eelgrass restoration in
Buzzards Bay. We spent some time on the water deploying and retrieving
sensors, worked out a few beginning of the season technical glitches,
and ran through a crash course on downloading data from ERDDAP.

Figure 1 – Attaching some extra weights to the line before
dropping a TDO logger overboard in Buzzards Bay
In the middle of the week, Huanxin and George visited Plymouth and
Cotuit to set up long-time non-realtime eMOLT participant Captain Todd
on the F/V Voyager and newcomer Captain Jake on the F/V Cornerstone.
Several of our partners have also been busy. Thanks to Coonamesset Farm
Foundation and the Center for Coastal Studies, we’re happy to welcome
the F/Vs Aarsheim Junior, Selje, Kimberly Ann, and Storm Elizabeth to
the eMOLT Program.
This week, the eMOLT fleet recorded 113 tows of sensorized fishing
gear totaling 264 sensor hours underwater. The warmest recorded bottom
temperature was 51 F near Atlantis Canyon in approximately 87 fathoms
(red profile) and the coldest recorded bottom temperature was 39 F
southeast of Boon Island in approximately 56 fathoms (blue profile).
Seasonal stratification is visible in profiles from around the
region, with the exception of profiles east of Penobscot Bay (black
profile shows no stratification).

Figure 2 – Temperature profiles collected by eMOLT participants
over the last week. The blue profile is where the coldest bottom
temperature was measured and the red profile is where the warmest bottom
temperature was measured. All other colors are assigned randomly.
Colored points on the map indicate where profiles of the same color were
collected. The small dark green dots represent other profiles collected
this week, but not highlighted in the plot. Note that the warmest /
coldest bottom temperatures measured could have occurred during gear
soaks, which are not represented on this profile plot.
Drifter Program Kicks off 2025 Season
The drifter program has begun its 2025 season. Falmouth High School
(Falmouth, MA), in coordination with Educational Passages, had a set of
units deployed by R/V Tioga on April 8th off Plymouth. As seen in the
animation below, they all came ashore within the first week after a few
days of strong northerlies. This cluster included 2 miniboats (ashore
the first day), 2 mini-drifters, and one standard drifter. The standard
drifter stayed out the longest. It actually entered the canal where, a
few days later, a large pod of right whales were sighted, documenting
the possibility that the surface plankton they hunt was advected that
way.

Figure 3 – gif showing movements of of drifters (green),
MakerBuoys (blue), and miniboats (cyan) along with FVCOM modeled surface
temps and currents, and eMOLT bottom temps (white numbers).
Two other drifters, built by Southern Maine Community College
students, were deployed this past week off Southern Maine by F/V Captain
B and F/V Tenacious II, respectively, and can be tracked here.
New Subsurface Observations Map
In an effort to put the value of the data you all collect into
perspective, we’ve developed a map of publicly available subsurface
observations from around the region that we will update weekly. All of
these data are available on ERDDAP servers (a sort of “industry
standard” for making oceanographic data available). To orient you to the
map, the pink dots are the locations of buoys operated by the Northeast
Regional Association of Coastal Ocean Observing Systems (NERACOOS) that
include subsurface observations of temperature and salinity. Blue dots
are observations from sensors on fishing vessels collected by
participants in the eMOLT Program, one of the Commercial Fisheries
Research Foundation’s programs, or one of Ocean Data Network’s programs.
These observations are mostly water temperature, although some of
vessels also deploy salinity and dissolved oxygen sensors. Red dots are
observations from gliders affiliated with the Rutgers University Center
for Ocean Observing Leadership and include a range of variables
including temperature, salinity, chlorophyll levels, dissolved oxygen,
nitrates, pH, and more. Brown dots are observations from the Argo
Program, which deploys floats around the world, and include a range of
variables including temperature, dissolved oxygen, salinity,
chlorophyll, turbidity, and nitrates. Finally, purple dots are
observations taken aboard the M/V Oleander using an Expendable
Bathythermograph (XBT). These observations include temperature and
salinity. You can see that on the shelf, there really isn’t much
subsurface data available in many areas without observations from the
fleet.

Figure 4 – Map of realtime, publicly accessible subsurface
measurements collected over the last month here in the Northeastern
United States. Fishing vessel observations (blue) represent aggregated
data from eMOLT, Commercial Fisheries Research Foundation, and Ocean
Data Network.
To learn more about the programs shown on this map, check out their
websites:
New Forecast Model Run Released
A new bottom temperature forecast for the region from a downscaled
version of the MOM6 (Modular Ocean Model) model is available. To
check out a video of this forecast through the end of the calendar year,
click here.
Per Dr. Vincent Saba at the Geophysical Fluid Dynamic Laboratory, the
southern Mid-Atlantic Bight is forecasted to be warm, but the Gulf of
Maine and parts of Georges Bank are forecasted to be cooler than
average. We’ll dig more into the model outputs in the coming weeks and
see about including comparisons like we do for Doppio.
System Hardware Upgrade List
The following vessels remain on our list for hardware upgrades. If
you aren’t on the list and think you should be, please reach out.
Note that this list is different from our new install
queue.
- F/V Kaitlyn Victoria
- F/V Kyler C
- F/V Noella C
- F/V Sea Watcher I
Bottom Temperature Forecasts
Doppio
This week, 90.3% of bottom temperature observations were within 2
degrees (F) of the Doppio forecasted value at those points. Most of the
tows this week took place in areas where the model has performed well
previously (in Massachusetts Bay and south of Long Island). Temps were a
cooler than expected east of New Jersey and warmer than expected along
the shelf edge.

Figure 5 – Performance of the Doppio forecast’s bottom
temperature layer over the last week relative to observations collected
by eMOLT participants. Red dots indicate areas where bottom temperature
observations were warmer that predicted. Blue dots indicate areas where
bottom temperature observations were cooler than predicted. Bottom
temperature observations are compared with the most recent forecast run
available before the observation was made.

Figure 6 – The most recent Doppio bottom temperature forecast.
The gray line is the 50 fathom line and the black line is the hundred
fathom line. Purple shades indicate cooler water.
Northeast Coastal Ocean Forecast System

Figure 7 – The most recent bottom temperature forecast from the
Northeast Coastal Ocean Forecast System GOM7 model. The gray line is the
50 fathom line and the black line is the hundred fathom line. Purple
shades indicate cooler water.

Figure 8 – The most recent bottom temperature forecast from the
Northeast Coastal Ocean Forecast System MassBay model. Purple shades
indicate cooler water.
Disclaimer
The eMOLT Update is NOT an official NOAA document. Mention of
products or manufacturers does not constitute an endorsement by NOAA or
Department of Commerce. The content of this update reflects only the
personal views of the authors and does not necessarily represent the
views of NOAA Fisheries, the Department of Commerce, or the United
States.
All the best,
-George